SHREWSBURY, Mass., June 22 /PRNewswire-FirstCall/ -- TranXenoGen, Inc. ("TranXenoGen" or the "Company"), announced today that the United States Patent and Trademark Office has issued a patent (No. 6,753,457) covering a method of reprogramming somatic cell nuclei for the production of cloned animals or embryos using nuclear transfer techniques. The technique, which is a key step in the cloning process, has broad applications in human therapeutics and agriculture, including the production of biopharmaceuticals in transgenic animals, generation of organs for xenotransplantation and the development of stem cell lines.

TranXenoGen is the exclusive licensee of the US patent, which issued to Brandeis University. The patent entitled "Nuclear Reprogramming Using Cytoplasmic Extract" is one of five issued patents licensed to the Company covering the nuclear reprogramming technology. The Company is seeking to out- license the technology in several key areas such as stem cell research, livestock and pet cloning as well as to establish research collaborations to aid in the commercialization of the technology.

Mr. George Uveges stated that, "As we outlined in our 2003 Annual Report, the Company's short-term revenue focus includes the marketing of the Company's patent portfolio. The issuance of this cloning patent is a significant step in enhancing the value of and monetizing the Company's patent portfolio."

Risk Warning Notice:

TranXenoGen, Inc. is a publicly traded development stage, biotechnology company that is focused on developing new therapeutic production technologies and products. Its shares are quoted on the Alternative Investment Market of the London Stock Exchange. The securities of the Company have not been registered under the Securities Act of 1933 and therefore, may not be offered or sold in the United States absent registration or an applicable exemption from the registration requirements under such Act.

TranXenoGen is a development stage company and, as such, investors should be aware that an investment in the Company involves a substantially high degree of risk.

This press release contains forward-looking statements that can be identified by terminology such as "expects", "potential", "suggests", "may", "will" or similar expressions. Such forward-looking statements regarding our business, which are not historical facts, are "forward-looking statements" that involve risk and uncertainties, which could cause the Company's actual results and financial condition to differ materially from those anticipated by the forward-looking statements. Actual results may differ materially from statements made as a result of various factors, including, but not limited to sufficiency of cash to fund the Company's planned operations, risk associated with inherent uncertainty of product research and development, risk of protecting proprietary rights and competition. Forward-looking statements speak only as to the date they are made. The Company does not undertake to update forward-looking statements to reflect the circumstances or events that occur after the date the forward-looking statements are made.